CSAS/CSAS6 Update for SCALE 4.4 and 4.4a: README file     Feb. 19, 2002

Description of Updates
----------------------
This update is to correct an error in the PC version of SCALE 4.4 and 
4.4a. No update is necessary for the Unix version.

A user recently reported a discrepancy between Dancoff factors
calculated by the PC and Unix versions of CSAS in SCALE 4.4a. The
discrepancy was corrected by recompiling subroutine DANCOF in MIPLIB
with no optimization. This discrepancy had never been observed before.
After a lengthy investigation, we have some observations, but no
definite conclusions, regarding the circumstances where the discrepancy
occurs. For the vast majority of cases, no discrepancy occurs. A small
discrepancy has been observed in cases with the standard composition
ZIRC2 as the clad material, but a more significant discrepancy has been
observed with standard composition ZIRC4 as the clad material. The clad
thickness also appears to be a factor: the discrepancy occurs in cases
with thicker clad. Users of the PC version of SCALE should install the
updated versions of CSAS and CSAS6 and test their LATTICECELL cases to
determine what impact, if any, this discrepancy has on their calculated
results. 

CSAS and CSAS6 were relinked with the unoptimized version of DANCOF. The
shielding control modules SAS1 and SAS4 were not updated because the
Dancoff factor is generally not important in radiation shielding
calculations. SAS2 does not use the DANCOF routine in MIPLIB and is not
affected.


Installation of Updates 
----------------------- 
SCALE 4.4a:
Download csas-csas6-update.exe and install in the
directory where SCALE 4.4a is already installed. The files will
automatically be installed in the appropriate subdirectories.

SCALE 4.4:
Download csas-csas6-update4.4.exe and install in the
directory where SCALE 4.4 is already installed. The files will
automatically be installed in the appropriate subdirectories.